Publications Details

An analysis of parameters affecting slapdown of transportation packages

Bergmann, V.L.; Ammerman, D.J.

In the certification of packages for transport of radioactive material, the issue of slapdown must be addressed. Slapdown is a secondary impact of the body caused by rotational accelerations induced during eccentric primary impact. In this report, several parameters are evaluated that affect slapdown severity of packages for the transport of nuclear material. The nose and tail accelerations in a slapdown event are compared to those experienced by the same cask in a side-drop configuration, in which there is no rotation, for a range of initial impact angles, impact limiter models, and friction coefficients for two existing cask geometries. In some cases, the rotation induced during a shallow-angle impact is sufficient to cause accelerations at the tail during secondary impact to be greater than those at the nose during initial impact. Furthermore, both nose and tail accelerations are often greater than the side-on accelerations. The results described here have been calculated using the code SLAPDOWN, which approximates the impact response of deformable bodies. Finally, SLAPDOWN has been used to estimate the coefficient of friction acting at the nose and tail for one particular cask during one specific slapdown drop test by comparison of results with experimental data. 2 refs., 16 figs., 3 tabs.